Ammonium Ferrous Sulphate

Ammonium ferrous sulphate is supplied for laboratory analysis redox reactions and industrial testing.

Ammonium Ferrous Sulphate, commonly known as

Mohr’s Salt, is a light green crystalline double salt with the chemical formula.  It is a staple in analytical chemistry because it provides a highly stable source of ferrous ions that resist oxidation by air much better than other iron salts. 

Key Properties & Characteristics 
Physical Appearance: It typically exists as pale green or bluish-green monoclinic crystals.
Stability: Unlike standard ferrous sulfate, Mohr’s salt has a long shelf life and is relatively resistant to oxidation.
Solubility: It is highly soluble in water, dissolving to form an acidic solution (pH ~3).
Molecular Weight: 392.14 g/mol for the hexahydrate form. 

Common Applications 
Analytical Chemistry: Primarily used as a primary standard in redox titrations (e.g., standardising potassium permanganate).
Dosimetry: Utilized in Fricke’s dosimeter to measure high doses of gamma radiation.
Industrial Uses: Used in water purification, metallurgy, and as an additive in certain fertilizers to treat iron deficiencies in plants.
Medical & Research: Historically used in medicine and as a ferroptosis inducer in biochemical research. 

Safety & Handling 
Hazard Rating: Classified as a GHS Warning substance; it can cause skin, eye, and respiratory irritation if handled improperly.
Precautions: Wear safety goggles and gloves. It should be stored in a cool, dry place and is sensitive to light and air.
Combustion: If burned, it releases toxic gases including sulfur and nitrogen oxides.